Method for treating fecal incontinence

ABSTRACT

A method for treating fecal incontinence in a body of a mammal having a rectum formed by a rectal wall extending to an anus wherein the rectal wall includes a sphincter muscle surrounding the anus. At least one nonaqueous solution is introduced into the rectal wall in the vicinity of the anus. A nonbiodegradable solid is formed in the rectal wall from the at least one nonaqueous solution.

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/286,245 filed Apr. 5, 1999 now U.S. Pat. No. 6,251,063,which is a continuation-in-part of U.S. patent application Ser. No.09/232,056 filed Jan. 15, 1999, now U.S. Pat. No. 6,238,355 and claimspriority to U.S. provisional patent application Serial No. 60/111,884filed Dec. 11, 1998, the entire contents of each of which areincorporated herein by this reference.

This invention pertains to the treatment of the gastrointestinal tractand, more particularly, to the treatment of fecal incontinence.

Fecal incontinence, which is most common in the elderly, is the loss ofvoluntary control to retain stool in the rectum. In most cases, fecalincontinence is the result of an impaired involuntary internal analsphincter. The internal sphincter may be incompetent due to laxity ordiscontinuity. Discontinuity, or disruption of the internal analsphincter, can be caused by a number of different muscle injuries.

In most patients, fecal incontinence is initially treated withconservative measures, such as biofeedback training or alteration of thestool consistency. Biofeedback is successful in approximately two-thirdsof patients who retain some degree of rectal sensation and functioningof the external anal sphincter. However, multiple sessions are oftennecessary, and patients need to be highly motivated. Electronic homebiofeedback systems are available and may be helpful as adjuvanttherapy.

Several surgical approaches to fecal incontinence have been tried, withvarying success, when conservative management has failed. Thesetreatments include sphincter repair, gracilis or gluteus muscletransposition to reconstruct an artificial sphincter and colostomy. Theapproach that is used depends on the cause of the incontinence and theexpertise of the surgeon. For example, biodegradable compounds have beeninjected or introduced into the anal sphincter to bulk the rectal wall.Unfortunately, such biodegradable compounds are resorbed by the body andthus become ineffective over time.

In general, it is an object of the present invention to provide aminimally invasive method and apparatus for treating fecal incontinence.

Another object of the invention is to provide a method of the abovecharacter for treating fecal incontinence in which one or more implantsare formed in the rectal wall.

Another object of the invention is to provide a method of the abovecharacter for treating fecal incontinence in which one or more implantsare formed in the rectal wall in the vicinity of the anal sphincter.

Another object of the invention is to provide a method of the abovecharacter in which one or more implants of a nonbiodegradable materialare formed in the anal sphincter for reducing the distensibility of theanal sphincter.

Additional objects and features of the invention will appear from thefollowing description from which the preferred embodiments are set forthin detail in conjunction with the accompanying drawings.

FIG. 1 is a sectional view of a portion of the human body in which aportion of the anal sphincter is being treated by a method of thepresent invention.

FIG. 2 is a cross-sectional view of a portion of the anal sphinctertaken along the line 2—2 of FIG. 1.

FIG. 3 is a sectional view of a portion of the human body similar toFIG. 1 in which a portion of the anal sphincter is being treated byanother method of the present invention.

FIG. 4 is a sectional view of a portion of the human body similar toFIG. 1 in which a portion of the anal sphincter is being treated by afurther method of the present invention.

FIG. 5 is a sectional view of a portion of the human body similar toFIG. 1 in which a portion of the anal sphincter is being treated by yetanother method of the present invention.

FIG. 6 is a cross-sectional view taken along the line 6—6 of FIG. 5.

FIG. 7 is a perspective view of an apparatus for use in the method fortreating the anal sphincter of the present invention.

In general, a method for treating fecal incontinence in the body of amammal having a rectum formed by a rectal wall extending to an anuswherein the rectal wall includes a sphincter muscle surrounding the anusis provided. At least one nonaqueous solution is introduced into therectal wall in the vicinity of the anus. A nonbiodegradable solid isformed in the rectal wall from the nonaqueous solution.

As shown in FIG. 1, the gastrointestinal tract includes the rectum 21and opens to the outside of body 22 at the anus 23. The rectum 21 isformed by a rectal wall 24 substantially centered on a centerline 25 ofthe rectum (see FIG. 3). The inner layer of the rectal wall 24 ismucosal layer 26, below which is submucosal layer 27. A layer of muscleextends around rectum 21 and also forms part of rectal wall 24. Suchmuscle layer comprises circular muscle layer 28 extending beneathsubmucosal layer 27 and longitudinal muscle layer 29 extending beneathcircular muscle layer 28. Body 22 further includes the anal sphincter 31having the sphincter ani internus 32 and the sphincter ani externus 33.Sphincter ani internus 32, an involuntary sphincter, forms the terminusof circular muscle layer 28 at anus 23. Sphincter ani externus 33, avoluntary sphincter, comprises a deep external sphincter 34, thesuperficial external sphincter 36 and the subcutaneous externalsphincter 37. For purposes of this application, the transition betweencircular muscle 28 and internal sphincter 32 comprises the transitionbetween rectum 21 and anus 23, also known as the anorectal border 38.Also for purposes of this application, rectal wall 24 and thus the wallof the gastrointestinal tract of body 22 includes both sphincter aniinternus 32 and sphincter ani externus 33 and thus, the wall of anus 23.Between external and internal sphincters 33 and 32 there exists thepotential space known as the intersphincteric space 39.

In the method for treating fecal incontinence of the present invention,an implantable material such as an implant-forming material or solutionis introduced into rectal wall 24 in the vicinity of anal sphincter 31by any suitable means to augment, bulk or otherwise decrease thedistensibility of the anal sphincter 31. The method of the presentinvention can be performed with any of the apparatus disclosed in U.S.patent application Ser. No. 09/286,245 filed Apr. 5, 1999 and U.S.patent application Ser. No. 09/232,056 filed Jan. 15, 1999. Onepreferred apparatus for introducing the solution into rectal wall 24includes a conventional syringe 41 having a barrel 42 filled with thesolution. A conventional elongate needle 43 is connected to syringe 41for delivering the solution from barrel 42 into rectal wall 24. Tubularneedle 43 can be of a conventional type and, as such, provided with asingle opening at the distal end thereof. Alternatively, needle 43 canbe similar to any of the needles described in U.S. patent applicationSer. No. 09/232,056 filed Apr. 5, 1999. Syringe 41 is part of the supplyassembly of the apparatus of the invention for depositing one or moreimplants in the rectal area of the patient, and more particularly is afirst reservoir containing the implant-forming material. Preferably, thesupply assembly further includes a second reservoir containing asolvent, preferably a biocompatible solvent such as dimethyl sulfoxide(DMSO), and a third reservoir containing a suitable aqueous orphysiologic solution such as saline.

Although any suitable implant-forming material can be used with themethod and/or apparatus of the present invention, one such material isat least one solution which when introduced into the body forms anonbiodegradable solid. As used herein, a solid means any substance thatdoes not flow perceptibly under moderate stress, has a definite capacityfor resisting forces which tend to deform it (such as compression,tension and strain) and under ordinary conditions retains a definitesize and shape; such a solid includes, without limitation, spongy and/orporous substances. One such embodiment of the at least one solution isfirst and second solutions which when combined in the body form thenonbiodegradable solid. Another such embodiment is a nonaqueous solutionwhich can be introduced into the body as a liquid and from which a solidthereafter precipitates. A preferred embodiment of such a nonaqueous orimplant-forming solution is a solution of a biocompatible polymer and abiocompatible solvent which can optionally include a contrast agent forfacilitating visualization of the solution in the body.

In one embodiment, an implant-forming solution is used that has acomposition comprising from about 2.5 to about 8.0 weight percent of abiocompatible polymer, from about 52 to about 87.5 weight percent of abiocompatible solvent and optionally from about 10 to about 40 weightpercent of a biocompatible contrast agent having a preferred averageparticle size of about 10 μm or less. It should be appreciated that anypercents stated herein which include a contrast agent would beproportionally adjusted when the contrast agent is not utilized. Anycontrast agent is preferably a water insoluble biocompatible contrastagent. The weight percent of the polymer, contrast agent andbiocompatible solvent is based on the total weight of the completecomposition. In a preferred embodiment, the water insoluble,biocompatible contrast agent is selected from the group consisting ofbarium sulfate, tantalum powder and tantalum oxide. In still a furtherpreferred embodiment, the biocompatible solvent is dimethylsulfoxide(DMSO), ethanol, ethyl lactate or acetone.

The term “biocompatible polymer” refers to polymers which, in theamounts employed, are non-toxic, chemically inert, and substantiallynon-immunogenic when used internally in the patient and which aresubstantially insoluble in physiologic liquids. Suitable biocompatiblepolymers include, byway of example, cellulose acetates (includingcellulose diacetate), ethylene vinyl alcohol copolymers, hydrogels(e.g., acrylics), poly(C₁-C₆) acrylates, acrylate copolymers, polyalkylalkacrylates wherein the alkyl and alk groups independently contain oneto six carbon atoms, polyacrylonitrile, polyvinylacetate, celluloseacetate butyrate, nitrocellulose, copolymers of urethane/carbonate,copolymers of styrene/maleic acid, and mixtures thereof. Copolymers ofurethane/carbonate include polycarbonates that are diol terminated whichare then reacted with a diisocyanate such as methylene bisphenyldiisocyanate to provide for the urethane/carbonate copolymers. Likewise,copolymers of styrene/maleic acid refer to copolymers having a ratio ofstyrene to maleic acid of from about 7:3 to about 3:7. Preferably, thebiocompatible polymer is also non-inflammatory when employed in situ.The particular biocompatible polymer employed is not critical and isselected relative to the viscosity of the resulting polymer solution,the solubility of the biocompatible polymer in the biocompatiblesolvent, and the like. Such factors are well within the skill of theart.

The polymers of polyacrylonitrile, polyvinylacetate, poly(C₁-C₆)acrylates, acrylate copolymers, polyalkyl alkacrylates wherein the alkyland alk groups independently contain one to six carbon atoms, celluloseacetate butyrate, nitrocellulose, copolymers of urethane/carbonate,copolymers of styrene/maleic acid and mixtures thereof typically willhave a molecular weight of at least about 50,000 and more preferablyfrom about 75,000 to about 300,000.

Preferred biocompatible polymers include cellulose diacetate andethylene vinyl alcohol copolymer. In one embodiment, the cellulosediacetate has an acetyl content of from about 31 to about 40 weightpercent. Cellulose diacetate polymers are either commercially availableor can be prepared by art recognized procedures. In a preferredembodiment, the number average molecular weight, as determined by gelpermeation chromatography, of the cellulose diacetate composition isfrom about 25,000 to about 100,000 more preferably from about 50,000 toabout 75,000 and still more preferably from about 58,000 to 64,000. Theweight average molecular weight of the cellulose diacetate composition,as determined by gel permeation chromatography, is preferably from about50,000 to 200,000 and more preferably from about 100,000 to about180,000. As is apparent to one skilled in the art, with all otherfactors being equal, cellulose diacetate polymers having a lowermolecular weight will impart a lower viscosity to the composition ascompared to higher molecular weight polymers. Accordingly, adjustment ofthe viscosity of the composition can be readily achieved by mereadjustment of the molecular weight of the polymer composition.

Ethylene vinyl alcohol copolymers comprise residues of both ethylene andvinyl alcohol monomers. Small amounts (e.g., less than 5 mole percent)of additional monomers can be included in the polymer structure orgrafted thereon provided such additional monomers do not alter theimplanting properties of the composition. Such additional monomersinclude, by way of example only, maleic anhydride, styrene, propylene,acrylic acid, vinyl acetate and the like.

Ethylene vinyl alcohol copolymers are either commercially available orcan be prepared by art recognized procedures. Preferably, the ethylenevinyl alcohol copolymer composition is selected such that a solution of8 weight-volume percent of the ethylene vinyl alcohol copolymer in DMSOhas a viscosity equal to or less than 60 centipoise at 20° C. and morepreferably 40 centipoise or less at 20° C. As is apparent to one skilledin the art, with all other factors being equal, copolymers having alower molecular weight will impart a lower viscosity to the compositionas compared to higher molecular weight copolymers. Accordingly,adjustment of the viscosity of the composition as necessary for catheterdelivery can be readily achieved by mere adjustment of the molecularweight of the copolymer composition.

As is also apparent, the ratio of ethylene to vinyl alcohol in thecopolymer affects the overall hydrophobicity/hydrophilicity of thecomposition which, in turn, affects the relative watersolubility/insolubility of the composition as well as the rate ofprecipitation of the copolymer in an aqueous solution. In a particularlypreferred embodiment, the copolymers employed herein comprise a molepercent of ethylene of from about 25 to about 60 and a mole percent ofvinyl alcohol of from about 40 to about 75, more preferably a molepercent of ethylene of from about 40 to about 60 and a mole percent ofvinyl alcohol of from about 40 to about 60.

The term “contrast agent” refers to a biocompatible (non-toxic)radiopaque material capable of being monitored during injection into amammalian subject by, for example, radiography. The contrast agent canbe either water soluble or water insoluble. Examples of water solublecontrast agents include metrizamide, iopamidol, iothalamate sodium,iodomide sodium, and meglumine. The term “water insoluble contrastagent” refers to contrast agents which are insoluble in water (i.e., hasa water solubility of less than 0.01 milligrams per milliliter at 20°C.) and include tantalum, tantalum oxide and barium sulfate, each ofwhich is commercially available in the proper form for in vivo use andpreferably having a particle size of 10 μm or less. Other waterinsoluble contrast agents include gold, tungsten and platinum powders.Methods for preparing such water insoluble biocompatible contrast agentshaving an average particle size of about 10 μm or less are describedbelow. Preferably, the contrast agent is water insoluble (i.e., has awater solubility of less than 0.01 mg/ml at 20° C.)

The term “biocompatible solvent” refers to an organic material liquid atleast at body temperature of the mammal in which the biocompatiblepolymer is soluble and, in the amounts used, is substantially non-toxic.Suitable biocompatible solvents include, by way of example,dimethylsulfoxide, analogues/homologues of dimethylsulfoxide, ethanol,ethyl lactate, acetone, and the like. Aqueous mixtures with thebiocompatible solvent can also be employed provided that the amount ofwater employed is sufficiently small that the dissolved polymerprecipitates upon injection into a human body. Preferably, thebiocompatible solvent is ethyl lactate or dimethylsulfoxide.

The term “encapsulation” as used relative to the contrast agent beingencapsulated in the precipitate is not meant to infer any physicalentrapment of the contrast agent within the precipitate much as acapsule encapsulates a medicament. Rather, this term is used to meanthat an integral coherent precipitate forms which does not separate intoindividual components, for example into a copolymer component and acontrast agent component.

The compositions employed in the methods of this invention are preparedby conventional methods whereby each of the components is added and theresulting composition mixed together until the overall composition issubstantially homogeneous. For example, sufficient amounts of theselected polymer are added to the biocompatible solvent to achieve theeffective concentration for the complete composition. Preferably, thecomposition will comprise from about 2.5 to about 20.0 weight percent ofthe polymer based on the total weight of the composition and morepreferably from about 4 to about 12 weight percent. If necessary, gentleheating and stirring can be used to effect dissolution of the polymerinto the biocompatible solvent, e.g., 12 hours at 50° C.

Sufficient amounts of the contrast agent are then optionally added tothe biocompatible solvent to achieve the effective concentration for thecomplete composition. Preferably, the composition will comprise fromabout 10 to about 40 weight percent of the contrast agent and morepreferably from about 20 to about 40 weight percent and even morepreferably about 30 to about 35 weight percent. When the contrast agentis not soluble in the biocompatible solvent, stirring is employed toeffect homogeneity of the resulting suspension. In order to enhanceformation of the suspension, the particle size of the contrast agent ispreferably maintained at about 10 μm or less and more preferably at fromabout 1 to about 5 μm (e.g., an average size of about 2 μm). In onepreferred embodiment, the appropriate particle size of the contrastagent is prepared, for example, by fractionation. In such an embodiment,a water insoluble contrast agent such as tantalum having an averageparticle size of less than about 20 microns is added to an organicliquid such as ethanol (absolute) preferably in a clean environment.Agitation of the resulting suspension followed by settling forapproximately 40 seconds permits the larger particles to settle faster.Removal of the upper portion of the organic liquid followed byseparation of the liquid from the particles results in a reduction ofthe particle size which is confirmed under an optical microscope. Theprocess is optionally repeated until a desired average particle size isreached.

The particular order of addition of components to the biocompatiblesolvent is not critical and stirring of the resulting suspension isconducted as necessary to achieve homogeneity of the composition.Preferably, mixing/stirring of the composition is conducted under ananhydrous atmosphere at ambient pressure. The resulting composition isheat sterilized and then stored preferably in sealed amber bottles orvials until needed.

Each of the polymers recited herein is commercially available but canalso be prepared by methods well known in the art. For example, polymersare typically prepared by conventional techniques such as radical,thermal, UV, gamma irradiation, or electron beam induced polymerizationemploying, as necessary, a polymerization catalyst or polymerizationinitiator to provide for the polymer composition. The specific manner ofpolymerization is not critical and the polymerization techniquesemployed do not form a part of this invention. In order to maintainsolubility in the biocompatible solvent, the polymers described hereinare preferably not cross-linked.

In another particularly preferred embodiment of the implant-forming oraugmenting solution, the biocompatible polymer composition can bereplaced with a biocompatible prepolymer composition containing abiocompatible prepolymer. In this embodiment, the composition comprisesa biocompatible prepolymer, an optional biocompatible water insolublecontrast agent preferably having an average particle size of about 10 μmless and, optionally, a biocompatible solvent.

The term “biocompatible prepolymer” refers to materials which polymerizein situ to form a polymer and which, in the amounts employed, arenon-toxic, chemically inert, and substantially non-immunogenic when usedinternally in the patient and which are substantially insoluble inphysiologic liquids. Such a composition is introduced into the body as amixture of reactive chemicals and thereafter forms a biocompatiblepolymer within the body. Suitable biocompatible prepolymers include, byway of example, cyanoacrylates, hydroxyethyl methacrylate, siliconprepolymers, and the like. The prepolymer can either be a monomer or areactive oligomer. Preferably, the biocompatible prepolymer is alsonon-inflammatory when employed in situ.

Prepolymer compositions can be prepared by adding sufficient amounts ofthe optional contrast agent to the solution (e.g., liquid prepolymer) toachieve the effective concentration for the complete polymercomposition. Preferably, the prepolymer composition will comprise fromabout 10 to about 40 weight percent of the contrast agent and morepreferably from about 20 to about 40 weight percent and even morepreferably about 30 weight percent. When the contrast agent is notsoluble in the biocompatible prepolymer composition, stirring isemployed to effect homogeneity of the resulting suspension. In order toenhance formation of the suspension, the particle size of the contrastagent is preferably maintained at about 10 μm or less and morepreferably at from about 1 to about 5 μm (e.g., an average size of about2 μm).

When the prepolymer is liquid (as in the case of polyurethanes), the useof a biocompatible solvent is not absolutely necessary but may bepreferred to provide for an appropriate viscosity in the implant-formingsolution. Preferably, when employed, the biocompatible solvent willcomprise from about 10 to about 50 weight percent of the biocompatibleprepolymer composition based on the total weight of the prepolymercomposition. When a biocompatible solvent is employed, the prepolymericcomposition typically comprises from about 90 to about 50 weight percentof the prepolymer based on the total weight of the composition.

In a particularly preferred embodiment, the prepolymer is cyanoacrylatewhich is preferably employed in the absence of a biocompatible solvent.When so employed, the cyanoacrylate adhesive is selected to have aviscosity of from about 5 to about 20 centipoise at 20° C.

The particular order of addition of components is not critical andstirring of the resulting suspension is conducted as necessary toachieve homogeneity of the composition. Preferably, mixing/stirring ofthe composition is conducted under an anhydrous atmosphere at ambientpressure. The resulting composition is sterilized and then storedpreferably in sealed amber bottles or vials until needed.

Other suitable implant-forming materials for introduction into one orboth of muscle layers 201 and 202 include injectable bioglass asdescribed in Walker et al., “Injectable Bioglass as a PotentialSubstitute for Injectable Polytetrafluorethylene Particles”, J. Urol.,148:645-7, 1992, small particle species such as polytetrafluoroethylene(PTFE) particles in glycerine such as Polytef®, biocompatiblecompositions comprising discrete, polymeric and silicone rubber bodiessuch as described in U.S. Pat. Nos. 5,007,940, 5,158,573 and 5,116,387to Berg, biocompatible compositions comprising carbon coated beads suchas disclosed in U.S. Pat. No. 5,451,406 to Lawin, collagen and otherbiodegradable material of the type disclosed in U.S. Pat. No. 4,803,075to Wallace et al. and other known injectable materials.

Specific embodiments of implant-forming solutions suitable for use inthe apparatus and methods of the invention are described in U.S. Pat.Nos. 5,667,767 dated Sep. 16, 1997, U.S. Pat. No. 5,580,568 dated Dec.3, 1996 and U.S. Pat. No. 5,695,480 dated Dec. 9, 1997 and InternationalPublication Number WO 97/45131 having an International Publication Dateof Dec. 4, 1997, the entire contents of which are incorporated herein bythis reference.

A suitable supply assembly for depositing one or more implants in therectal area of the patient is coupled to the proximal extremity of theprobe member. The supply assembly includes at least a first reservoircontaining the implant-forming material. As noted above, suchimplant-forming solution preferably includes at least one nonaqueoussolution and more preferably is a solution of a biocompatible polymerand a biocompatible solvent. Preferably, the supply assembly furtherincludes a second reservoir containing a solvent and preferably abiocompatible solvent such as dimethyl sulfoxide (DMSO) and a thirdreservoir containing a suitable aqueous or physiologic solution such assaline.

In the method of the present invention, let it be assumed that inpreparing for the procedure, the gastrointestinal tract of a patient hasbeen previously evaluated by using any or all techniques and proceduresavailable in the art including, but not limited to, upper and lowergastrointestinal radiographic studies, motility studies, endoscopy withbiopsies, proctoscopy, sigmoidoscopy and colonoscopy. Assuming that thepatient's pretreatment evaluation warrants the procedure hereinafterdescribed and that the patient has received a typical surgical bowelpreparation as is known in the art, the patient can be brought into anoutpatient clinic or an operating room in a hospital. The patient ispreferably placed in either a lithotomy or jackknife position on anoperating or examining table or on a gurney.

After intravenous access has been accomplished and the patient has beenappropriately sedated or anesthetized, the physician inserts a suitableprobe member or scope, for example an anoscope, aproctoscope or asigmoidoscope, in a standard manner. After appropriate positioning ofthe scope to identify the appropriate region of the rectal wall 24 fortreatment, the scope is removed from the rectum. The physician or hisassistant then fills and primes syringe 41, in the manner described inU.S. patent application Ser. No. 09/286,245 filed Apr. 5,1999, with asaline or other suitable aqueous or physiological solution from thethird reservoir of the supply assembly, referred to herein as the salinesolution. The distal extremity of needle 43 is introduced through anus23 of the patient and passed into the region of anal sphincter 31 asseen in FIG. 1. In this regard, the handle of syringe 41 is grasped bythe physician in order to introduce the distal extremity of needle 43into anus 23 and advance it in a cephalad direction to the vicinity ofsphincter 31, the area to be treated. By subsequently advancing needle43 laterally, the physician penetrates wall 24 of anus 23 with thesharpened end of needle 43 which causes the distal end thereof topenetrate anal sphincter 31.

Alternatively, the scope can be maintained in anal canal 23 during theprocedure in order to maximize exposure and visibility. In such a case,needle 43 or a catheter-type needle, that is a needle at the end of acatheter, is advanced through the scope and beyond the distal endthereof to the area of treatment instead of being advanced directlythrough anus 23. It should also be appreciated that the treatment of thepresent invention can be performed with an appropriately modified biopsyguide in conjunction with a trans-rectal ultrasound system (TRUS).

In one of the embodiments of the invention the saline solution from thethird reservoir of the supply assembly can be injected into wall 24 andmore specifically into internal sphincter 32. The saline injectioncreates to a local edema for facilitating acceptance of the implant bythe body of the patient. The amount of injected saline solution canrange from 0.25 to 10 cc and preferably ranges from 1 to 3 cc.Thereafter, the physician retracts needle 43 from wall 24, removessyringe 41 from anus 23, subsequently withdrawing the remaining salinesolution from the needle passage and flushing the needle passage withDMSO from the second reservoir to ensure that the saline solution hasbeen removed from the passage. Removal of the saline solution from theneedle passage and the cleansing of the passage with DMSO inhibitspremature precipitation within syringe of the biocompatible polymer inthe implant-forming solution of the first reservoir from the DMSO insuch implant-forming solution. The needle passage is next primed withthe implanting-forming solution from the first reservoir.

The physician subsequently causes the distal portion of needle 43 topenetrate the internal sphincter and thereafter causes a preselectedamount of the implant-forming solution to be introduced through needle43. The optional contrast agent within the implant-forming solutionpermits the viewing of the solution by means of fluoroscopy. Inaddition, the introduction of the implant-forming solution into wall 24can be monitored by standard abdominal or pelvic ultrasound or,preferably, by high resolution trans-rectal ultrasound system. The rateof injection of the implant-forming solution into the space can rangefrom 0.1 cc per minute to 10 cc per minute. Once the implant-formingsolution has been introduced into wall 24, the biocompatible polymer ofthe implant-forming solution precipitates to form one or more discretedeposits or solid implants 51 (see FIGS. 1-2). The bio-compatiblesolvent disperses in body 22. The amount of implant-forming solutioninjected into wall 24 for each implant 51 can range from 0.05 cc to 10cc.

It has been found that an injection of a suitable aqueous or physiologicsolution such as a saline solution into wall 24 prior to the injectionof the implant-forming solution serves to condition or prepare thetissue in wall 24, that is to help wall 24 receive the implant-formingsolution and thus facilitate implantation of the biocompatible polymer.Although the conditioning solution has been described as a salinesolution, antibiotics and/or anti-inflammatories can be introducedlocally to condition the tissue. The use of a saline solution asdiscussed above also facilitates the rapid dispersion of the DMSO fromthe implant-forming solution thus diluting any local irritant effect ofthe DMSO. The saline solution further acts as a heat sink for the heatof dissolution of the solvent.

Any number and configuration of implants 51 can be formed in rectal wall24. In one preferred method, a plurality of circumferentiallyspaced-apart implants 51 are formed in rectal wall 24 (see FIGS. 1-2).The discrete implants 51 can be formed in submucosal layer 27, circularmuscle layer 28 and/or longitudinal muscle layer 29. In addition, theimplants 51 can be formed in anal sphincter 31, as shown in FIGS. 1-2where implants 51 are located in sphincter ani internus 32. It should beappreciated that implants 51 can also be formed in any or all of theportions of sphincter ani internus 32, sphincter ani externus 33,namely, deep external sphincter 34, superficial external sphincter 36and/or subcutaneous external sphincter 37, and/or in theintersphincteric space 39. An exemplary implant 52 formed by dashedlines is shown in each of deep external sphincter 34, superficialexternal sphincter 36 and subcutaneous external sphincter 37 in FIG. 1.

When a plurality of implants 51 are formed in rectal wall 24 in thevicinity of anus 23, such implants can be disposed substantially in aplane, as shown in FIGS. 1-2, in multiple planes or out of plane.Implants 51 can be symmetrically or asymmetrically disposed around anus23. Such implants can be formed from pulsed or continuous injections ofa solution from syringe 41 or by any other suitable manual or automatedmeans.

In a particularly preferred embodiment of the present invention one ormore elongate implants 53 having respective longitudinal axes 54 areformed in lax internal sphincter 32, as seen in FIG. 3, by using any ofthe solutions hereinbefore described. In order to perform the method insuch a manner, the physician utilizes a longer needle 43, preferably aneedle having a length of at least 3.5 to 5.0 inches, under directvision. Holding syringe 41 as hereinbefore described, the physicianadvances needle 43 similarly, in a cephalad and then lateral directioninto and through internal sphincter 32 until the distal end of needle 43abuts or approximates anorectal border 38, above internal sphincter 32.Using a pull-back technique of injection, the physician injects anddeposits implant-forming solution in the muscle of internal sphincter 32while slowly withdrawing needle 43, thereby creating an elongate,longitudinally oriented implant 53 therein. Preferably, rod-shapedimplants 53 formed in this manner have a length of approximately 20-100millimeters and a width of approximately 0.1 to 25 millimeters,depending on the dimensions of the sphincter being augmented or treated.

Elongate implants 53 preferably extend from the cephalad to caudal endsof internal sphincter 32 or from anorectal border 38 to opening of anus23. As such, the longitudinal axis of 54 each of the implants 53 extendssubstantially parallel to the centerline of the rectum. It should beappreciated that with this technique, while a single elongate implant 53can be deposited at any location within internal sphincter 32, a greaternumber of implants can be spaced apart therein. Preferably, at leastfour such implants are placed circumferentially, at approximately ninetydegrees of separation from one another, within internal anal sphincter32. Each quadrant of internal sphincter 32 is thereby enlisted toparticipate substantially equally in augmenting sphincter competency. Inthis manner elongate implants 53 bolster, stiffen and increase the tonusof an otherwise lax internal sphincter 32, helping to maintain andrestore the anatomical configuration and function thereof. Ashereinbefore described, diminished distensibility of internal sphincter32 ameliorates anal incontinence.

In another preferred embodiment, similar rod-like implants 53 are formedwithin a disrupted internal sphincter 32 in order to restore thestructural and functional integrity thereof as seen in FIG. 4. Theapparatus and technique of forming implants 53 are as hereinbeforedescribed. Any of the materials discussed above for creating implants ina body can be utilized. However, the implants are preferably formed froman injectable solution of a biocompatible polymer and a biocompatiblesolvent from which the biocompatible polymer precipitates when thesolution is introduced into the body. Inasmuch as the size anddistribution of an implant created depends in part upon the quantity ofimplant-forming material, speed of injection thereof and the space ortissue into which the material is injected, the technique of pull-backinjection utilized with this embodiment is performed particularly slowlyin order to form an elongate implant 53 which bridges the damaged orincompetent portion 60 of internal sphincter 32. Specifically, needle 43is extended up through the second end portion 59, the damaged portion 60and then the first end 58, before being slowly pulled back duringdelivery of the implant-forming material into the sphincter 32. Bybracing the damaged internal sphincter 32, function is restored and endportions 58 and 59 can again properly function together as a unit.

The elongate implants of the present invention can be formed in anyother portion of the wall of the gastrointestinal tract, or in any otherwall forming a passageway in a body of a mammal. In addition, thetechnique disclosed above for bracing or restoring a muscle, for examplea muscle having a damaged or incompetent portion, can be utilizedelsewhere in a body of a mammal. It should further be appreciated thatarc-shaped, arcuate and/or ring-shaped implants, for example of the typedisclosed in U.S. patent application Ser. No. 09/447,663 filed Nov. 23,1999, the entire content of which can be incorporated herein by thisreference, can also be formed in any of the muscle layers of the rectalwall 24.

In another particularly preferred embodiment of the present invention,one or more implants 55 are formed in intersphincteric space 39, as seenin FIGS. 5-6, either exclusively or in conjunction with internalsphincter implants 51 hereinbefore described. Techniques and apparatusare as hereinbefore described. The implants are preferably formed froman injectable solution of a biocompatible polymer and a biocompatiblesolvent from which the biocompatible polymer precipitates when thesolution is introduced into the body. In addition, intersphinctericspace 39 is located using pelvic ultrasound or, preferably, highresolution trans-rectal ultrasound. Preferably, intersphinctericimplants 55 are circumferentially spaced apart and arcuate or ring-likein configuration. In comparison to external or internal sphincters 33and 32, intersphincteric space 39 is substantially without striations,septa or fibrous bands and, as such, is more capacious. Therefore, afully circumferential ring-like implant can be much more easily formedtherein, for example by ejecting material laterally or horizontally outof side openings of needle 43. A circumferential intersphinctericimplant 55 facilitates augmentation of a lax anal sphincter 31. To thisend, preferably, the physician uses a needle 43 provided with aplurality of longitudinally and spaced-apart openings. In order tocreate a plurality of implants, multiple separate injections inintersphincteric space 39 are performed. Two arcuate implants are shownin FIGS. 5 and 6. A ring-shaped implant can be formed by forming aplurality of arcuate implants which abut each other to form thering-shaped implant.

The optional contrast agent in the implants permits the implants to bemonitored after completion of the procedure described above. Thus thestability of the implants and their configurations can be observed overtime. Further procedures can be performed to supplement previouslyformed implants. It should be appreciated that the implants of thepresent invention can be used as delivery vehicles for other materialssuch as radio-isotopes, chemotherapeutic agents, anti-inflammatoryagents and/or antibiotics.

The treatment of the invention can be reversed by expanding theaugmented or coapted region created by the implants in an suitablemanner such as by use of a balloon or bougie.

Although the method of the invention has been described as including theinjection of a saline solution into the wall 24 prior to an injection ofimplant-forming solution into the wall 24, it should be appreciated thatthe implant-forming solution can be injected into wall 24 without such aprior injection of saline or other solution. A saline or other aqueousor physiologic solution can optionally be introduced into the wall 24after the introduction of the implant-forming solution therein tofacilitate dispersion of the DMSO or other biocompatible solvent presentin the implant forming solution. It can thus be seen that the inventionis broad enough to cover the introduction of any conditioning solutioninto the tissue after the treatment to facilitate the treatment.

Although in the described method of the invention the delivery needlehas been introduced through the rectal wall, formation or placement ofimplants in or about the anal sphincter can be accomplishedtransperineally and be within the scope of the present invention. Inthis regard, one or more needles for delivery of the implant-formingmaterial can be introduced through the perineum for accessing the analsphincter, the intersphincteric space 39 and/or other tissue in thevicinity thereof. Such implant formation can be visualized and monitoredunder ultrasound or any other conventional means. As such, introductioninto the rectal wall can be accomplished from the rectal cavity orthrough the perineum.

It should be appreciated that additional configurations and types ofneedles are included within the purview of the present invention. Thus,needles provided with any combination of longitudinally and/orcircumferentially spaced-apart side openings can be used to facilitatethe formation of arcuate, thicker and/or wider implants. In addition toneedles carrying cutting tips, needles provided with blunt tips may beutilized.

It should also be appreciated that other apparatus can be utilized toaugment, bulk or otherwise decrease the distensibility of rectal wall 24in the vicinity of anus 23. For example, as shown in FIG. 7, a deliverymechanism or gun 56 which provides preselected amounts of the solutioninto rectal wall 24 can be utilized. Gun 56 is substantially similar tothe gun shown in U.S. patent application No. Ser. No. 09/286,245 filedApr. 5, 1999. Syringe 41 can be utilized with gun 56 and a stop cock 57can be disposed between syringe 41 and needle 43 for permitting abiocompatible solvent such as DMSO and/or an aqueous solution such assaline to be alternatively introduced through needle 43 into rectal wall24. Reservoirs such as additional syringes (not shown) can be utilizedin this regard.

It can be seen from the foregoing that the implants formed by the methodof the present invention can be of a variety of sizes and formed in avariety of configurations in the wall of the rectum and anal canal. Anymaterial or solution utilized for forming such implants can be injectedinto the wall in a variety of manual or automated and pulsed oncontinuous manners. One or more implants can be formed in any of thelayers of the wall, including any of the muscle layers or inter-muscularlayers of the wall. Without limiting the foregoing, it should beappreciated that any of the implants of the invention hereinbeforedescribed can be formed in any sphincter-like muscle or mechanism in thegastrointestinal tract or elsewhere in the body.

What is claimed is:
 1. A method for treating fecal incontinence in abody of a mammal having a rectum formed by a rectal wall extending to ananus wherein the rectal wall includes a sphincter muscle surrounding theanus and intersphincteric space comprising the steps of introducing atleast one nonaqueous solution into he rectal wall in the vicinity of theanus and forming from the at least one nonaqueous solution anonbiodegradable solid in the intersphincteric space of the rectal wall.2. The method of claim 1 wherein the forming step includes the step offorming a plurality of discrete nonbiodegradable solids in the rectalwall around the anus.
 3. The method of claim 2 wherein said forming stepincludes forming a plurality of rod-shaped solids.
 4. The method ofclaim 1 wherein the rectal wall includes an anorectal border and whereinthe forming step includes forming at least one solid extending from theanorectal border to the anus.
 5. The method of claim 1 wherein the solidis elongate in shape.
 6. The method of claim 1 wherein the solid isarcuate in shape.
 7. The method of claim 6 wherein the solid isring-shaped.
 8. The method of claim 1 wherein the introducing stepincludes the step of introducing the at least one nonaqueous solutioninto the sphincter muscle.
 9. The method of claim 8 wherein thesphincter muscle includes a sphincter ani internus and wherein theintroducing step includes the step of introducing the at least onenonaqueous solution into the sphincter ani internus.
 10. The method ofclaim 9 wherein the solid is elongate in shape.
 11. The method of claim8 wherein the sphincter muscle includes a sphincter ani externus andwherein the introducing step includes the step of introducing the atleast one nonaqueous solution into he sphincter ani externus.
 12. Themethod of claim 1 wherein the at least one solution is a solution of abiocompatible polymer and a biocompatible solvent and wherein theforming step includes the step of precipitating the biocompatiblepolymer from the solution so that the biocompatible polymer solidifiesin the rectal wall in the vicinity of the anus and the biocompatiblesolvent disperses in the body.
 13. The method of claim 12 wherein theintroducing step includes the steps of extending a needle into therectal wall and supplying the biocompatible polymer and thebiocompatible solvent through the needle into the rectal wall.
 14. Themethod of claim 13 wherein the extending step includes the step ofextending the needle from the rectal cavity into the rectal wall. 15.The method of claim 13 wherein the extending step includes the step ofextending the needle through the perineum into the rectal wall.
 16. Amethod for treating fecal incontinence in a body having an analsphincter with a damaged portion comprising the step of forming at leastone nonbiodegradable implant in said sphincter and bridging the damagedportion with the implant.
 17. The method of claim 16 further includingthe step of introducing at least one solution into said sphincter andforming said implant from the at least one solution.
 18. The method ofclaim 17 wherein the introducing step includes the steps of introducinga needle into the sphincter and introducing said at least one solutionthrough the needle into the sphincter.
 19. The method of claim 16wherein the anal sphincter has an internal sphincter and wherein theforming step includes the step of forming the at least one implant insaid internal sphincter.
 20. A method for treating fecal incontinence ina body of a mammal having a rectum formed by a rectal wall comprisingthe step of forming a rod-like implant in the rectal wall.
 21. Themethod of claim 20 wherein the rectum has a centerline and the rod-likeimplant has an axis extending substantially parallel to the centerlineof the rectum.
 22. The method of claim 21 wherein the forming stepincludes the step of introducing at least one nonaqueous solution intothe rectal wall.
 23. The method of claim 22 wherein the at least onenonaqueous solution is a solution of a biocompatible polymer and abiocompatible solvent and the forming step includes the step ofprecipitating the biocompatible polymer from the solution so that thebiocompatible polymer solidifies in the rectal wall in the vicinity ofthe anus and the biocompatible solvent disperses in the body.